The present invention relates to a method of checking authenticity of recorded information recorded on a recording medium or of confirming identity of recorded information recorded on a recording medium with original recorded information corresponding to the recorded information, using a contactless integrated circuit (IC) chip having recorded a unique identifier (ID) assigned thereto.
In an operation to transfer official documents to be transferred between government and municipal offices, companies, and/or individual persons or sheets of paper on which documents are recorded and which have value, for example, securities and/or notes, it is important to confirm authenticity thereof, namely, such items are actually associated with their original information. Items of which authenticity attracts attention due to value thereof include art objects, industrial art objects, and photos. In a situation in which it is required to confirm authenticity of various recorded information recorded on a recording medium in various forms such as characters and letters, graphic images, symbols, pseudo-solid contours, combinations of these items, and/or combinations of these items with colors, each of the recorded information becomes an object to be confirmed or checked.
One of the forms of recorded information is, for example, a document including a set of characters. In a most common method to confirm authenticity of a document, a seal impression is put on the document or a bar code is printed thereon. For example, in a commercial transaction, a partner of the transaction having received a document with a seal impression put thereon confirms authenticity of the document as follows. The receiver of the document makes a check to determine whether or not the seal impression is associated with a seal beforehand registered to, for example, a municipal office to resultantly confirm truth or falsehood of the document. In another case in which the document is generated as electronic information, a digital signature is used in place of the seal impression to confirm authenticity of the document. JP-A-11-238049 proposes another method of confirming authenticity of a document using summary information in place of the digital signature. This method produces summary information by applying a function, i.e., a summary function to each of information files of an original document and a document of which authenticity is to be confirmed. The method verifies the summary information with each other to resultantly confirm authenticity of the document.
However, the methods of the prior art are open to further improvement. For example, in the method using a seal impression, if the seal used to produce the seal impression is stolen and is put to a document including recorded information, authenticity of the document is normally and successfully achieved. That is, it is difficult to determine that the recorded information is actually true or false. The methods cannot be fully applicable to a document on which a bar code or the like including authentication information beforehand encoded. In this case, if a part of the bar code is cut off and is pasted on a document, authenticity of the document will be confirmed. On the other hand, the invention of JP-A-11-238049 describing the confirmation method of the prior art for electronically recorded information is also open to further improvement. The method is inherently limited to electronic documents. In addition, although forging and stealing of a digital signature and an electronic certificate require troublesome human power and a long period of time, if the forging or the like is successfully achieved, authenticity of such documents cannot be completely and satisfactorily confirmed. Heretofore, no method has been proposed which closely and not separably relates recorded information of a document, a graphic image, or the like recorded on one of various recording media such as a sheet of paper through a printing operation or the like to information indicating that the recorded information is actually produced from its original to thereby confirming authenticity of the recorded information.